/* * kernel/lockdep_proc.c * * Runtime locking correctness validator * * Started by Ingo Molnar: * * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> * * Code for /proc/lockdep and /proc/lockdep_stats: * */ #include <linux/export.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/kallsyms.h> #include <linux/debug_locks.h> #include <linux/vmalloc.h> #include <linux/sort.h> #include <asm/uaccess.h> #include <asm/div64.h> #include "lockdep_internals.h" static void *l_next(struct seq_file *m, void *v, loff_t *pos) { return seq_list_next(v, &all_lock_classes, pos); } static void *l_start(struct seq_file *m, loff_t *pos) { return seq_list_start_head(&all_lock_classes, *pos); } static void l_stop(struct seq_file *m, void *v) { } static void print_name(struct seq_file *m, struct lock_class *class) { char str[128]; const char *name = class->name; if (!name) { name = __get_key_name(class->key, str); seq_printf(m, "%s", name); } else{ seq_printf(m, "%s", name); if (class->name_version > 1) seq_printf(m, "#%d", class->name_version); if (class->subclass) seq_printf(m, "/%d", class->subclass); } } static int l_show(struct seq_file *m, void *v) { struct lock_class *class = list_entry(v, struct lock_class, lock_entry); struct lock_list *entry; char usage[LOCK_USAGE_CHARS]; if (v == &all_lock_classes) { seq_printf(m, "all lock classes:\n"); return 0; } seq_printf(m, "%p", class->key); #ifdef CONFIG_DEBUG_LOCKDEP seq_printf(m, " OPS:%8ld", class->ops); #endif #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class)); seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); #endif get_usage_chars(class, usage); seq_printf(m, " %s", usage); seq_printf(m, ": "); print_name(m, class); seq_puts(m, "\n"); list_for_each_entry(entry, &class->locks_after, entry) { if (entry->distance == 1) { seq_printf(m, " -> [%p] ", entry->class->key); print_name(m, entry->class); seq_puts(m, "\n"); } } seq_puts(m, "\n"); return 0; } static const struct seq_operations lockdep_ops = { .start = l_start, .next = l_next, .stop = l_stop, .show = l_show, }; static int lockdep_open(struct inode *inode, struct file *file) { return seq_open(file, &lockdep_ops); } static const struct file_operations proc_lockdep_operations = { .open = lockdep_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; #ifdef CONFIG_PROVE_LOCKING static void *lc_start(struct seq_file *m, loff_t *pos) { if (*pos == 0) return SEQ_START_TOKEN; if (*pos - 1 < nr_lock_chains) return lock_chains + (*pos - 1); return NULL; } static void *lc_next(struct seq_file *m, void *v, loff_t *pos) { (*pos)++; return lc_start(m, pos); } static void lc_stop(struct seq_file *m, void *v) { } static int lc_show(struct seq_file *m, void *v) { struct lock_chain *chain = v; struct lock_class *class; int i; if (v == SEQ_START_TOKEN) { seq_printf(m, "all lock chains:\n"); return 0; } seq_printf(m, "irq_context: %d\n", chain->irq_context); for (i = 0; i < chain->depth; i++) { class = lock_chain_get_class(chain, i); if (!class->key) continue; seq_printf(m, "[%p] ", class->key); print_name(m, class); seq_puts(m, "\n"); } seq_puts(m, "\n"); return 0; } static const struct seq_operations lockdep_chains_ops = { .start = lc_start, .next = lc_next, .stop = lc_stop, .show = lc_show, }; static int lockdep_chains_open(struct inode *inode, struct file *file) { return seq_open(file, &lockdep_chains_ops); } static const struct file_operations proc_lockdep_chains_operations = { .open = lockdep_chains_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; #endif /* CONFIG_PROVE_LOCKING */ static void lockdep_stats_debug_show(struct seq_file *m) { #ifdef CONFIG_DEBUG_LOCKDEP unsigned long long hi1 = debug_atomic_read(hardirqs_on_events), hi2 = debug_atomic_read(hardirqs_off_events), hr1 = debug_atomic_read(redundant_hardirqs_on), hr2 = debug_atomic_read(redundant_hardirqs_off), si1 = debug_atomic_read(softirqs_on_events), si2 = debug_atomic_read(softirqs_off_events), sr1 = debug_atomic_read(redundant_softirqs_on), sr2 = debug_atomic_read(redundant_softirqs_off); seq_printf(m, " chain lookup misses: %11llu\n", debug_atomic_read(chain_lookup_misses)); seq_printf(m, " chain lookup hits: %11llu\n", debug_atomic_read(chain_lookup_hits)); seq_printf(m, " cyclic checks: %11llu\n", debug_atomic_read(nr_cyclic_checks)); seq_printf(m, " find-mask forwards checks: %11llu\n", debug_atomic_read(nr_find_usage_forwards_checks)); seq_printf(m, " find-mask backwards checks: %11llu\n", debug_atomic_read(nr_find_usage_backwards_checks)); seq_printf(m, " hardirq on events: %11llu\n", hi1); seq_printf(m, " hardirq off events: %11llu\n", hi2); seq_printf(m, " redundant hardirq ons: %11llu\n", hr1); seq_printf(m, " redundant hardirq offs: %11llu\n", hr2); seq_printf(m, " softirq on events: %11llu\n", si1); seq_printf(m, " softirq off events: %11llu\n", si2); seq_printf(m, " redundant softirq ons: %11llu\n", sr1); seq_printf(m, " redundant softirq offs: %11llu\n", sr2); #endif } static int lockdep_stats_show(struct seq_file *m, void *v) { struct lock_class *class; unsigned long nr_unused = 0, nr_uncategorized = 0, nr_irq_safe = 0, nr_irq_unsafe = 0, nr_softirq_safe = 0, nr_softirq_unsafe = 0, nr_hardirq_safe = 0, nr_hardirq_unsafe = 0, nr_irq_read_safe = 0, nr_irq_read_unsafe = 0, nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0, nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0, sum_forward_deps = 0; list_for_each_entry(class, &all_lock_classes, lock_entry) { if (class->usage_mask == 0) nr_unused++; if (class->usage_mask == LOCKF_USED) nr_uncategorized++; if (class->usage_mask & LOCKF_USED_IN_IRQ) nr_irq_safe++; if (class->usage_mask & LOCKF_ENABLED_IRQ) nr_irq_unsafe++; if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ) nr_softirq_safe++; if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ) nr_softirq_unsafe++; if (class->usage_mask & LOCKF_USED_IN_HARDIRQ) nr_hardirq_safe++; if (class->usage_mask & LOCKF_ENABLED_HARDIRQ) nr_hardirq_unsafe++; if (class->usage_mask & LOCKF_USED_IN_IRQ_READ) nr_irq_read_safe++; if (class->usage_mask & LOCKF_ENABLED_IRQ_READ) nr_irq_read_unsafe++; if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) nr_softirq_read_safe++; if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ) nr_softirq_read_unsafe++; if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) nr_hardirq_read_safe++; if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ) nr_hardirq_read_unsafe++; #ifdef CONFIG_PROVE_LOCKING sum_forward_deps += lockdep_count_forward_deps(class); #endif } #ifdef CONFIG_DEBUG_LOCKDEP DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused); #endif seq_printf(m, " lock-classes: %11lu [max: %lu]\n", nr_lock_classes, MAX_LOCKDEP_KEYS); seq_printf(m, " direct dependencies: %11lu [max: %lu]\n", nr_list_entries, MAX_LOCKDEP_ENTRIES); seq_printf(m, " indirect dependencies: %11lu\n", sum_forward_deps); /* * Total number of dependencies: * * All irq-safe locks may nest inside irq-unsafe locks, * plus all the other known dependencies: */ seq_printf(m, " all direct dependencies: %11lu\n", nr_irq_unsafe * nr_irq_safe + nr_hardirq_unsafe * nr_hardirq_safe + nr_list_entries); #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " dependency chains: %11lu [max: %lu]\n", nr_lock_chains, MAX_LOCKDEP_CHAINS); seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n", nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS); #endif #ifdef CONFIG_TRACE_IRQFLAGS seq_printf(m, " in-hardirq chains: %11u\n", nr_hardirq_chains); seq_printf(m, " in-softirq chains: %11u\n", nr_softirq_chains); #endif seq_printf(m, " in-process chains: %11u\n", nr_process_chains); seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n", nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES); seq_printf(m, " combined max dependencies: %11u\n", (nr_hardirq_chains + 1) * (nr_softirq_chains + 1) * (nr_process_chains + 1) ); seq_printf(m, " hardirq-safe locks: %11lu\n", nr_hardirq_safe); seq_printf(m, " hardirq-unsafe locks: %11lu\n", nr_hardirq_unsafe); seq_printf(m, " softirq-safe locks: %11lu\n", nr_softirq_safe); seq_printf(m, " softirq-unsafe locks: %11lu\n", nr_softirq_unsafe); seq_printf(m, " irq-safe locks: %11lu\n", nr_irq_safe); seq_printf(m, " irq-unsafe locks: %11lu\n", nr_irq_unsafe); seq_printf(m, " hardirq-read-safe locks: %11lu\n", nr_hardirq_read_safe); seq_printf(m, " hardirq-read-unsafe locks: %11lu\n", nr_hardirq_read_unsafe); seq_printf(m, " softirq-read-safe locks: %11lu\n", nr_softirq_read_safe); seq_printf(m, " softirq-read-unsafe locks: %11lu\n", nr_softirq_read_unsafe); seq_printf(m, " irq-read-safe locks: %11lu\n", nr_irq_read_safe); seq_printf(m, " irq-read-unsafe locks: %11lu\n", nr_irq_read_unsafe); seq_printf(m, " uncategorized locks: %11lu\n", nr_uncategorized); seq_printf(m, " unused locks: %11lu\n", nr_unused); seq_printf(m, " max locking depth: %11u\n", max_lockdep_depth); #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " max bfs queue depth: %11u\n", max_bfs_queue_depth); #endif lockdep_stats_debug_show(m); seq_printf(m, " debug_locks: %11u\n", debug_locks); return 0; } static int lockdep_stats_open(struct inode *inode, struct file *file) { return single_open(file, lockdep_stats_show, NULL); } static const struct file_operations proc_lockdep_stats_operations = { .open = lockdep_stats_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #ifdef CONFIG_LOCK_STAT struct lock_stat_data { struct lock_class *class; struct lock_class_stats stats; }; struct lock_stat_seq { struct lock_stat_data *iter_end; struct lock_stat_data stats[MAX_LOCKDEP_KEYS]; }; /* * sort on absolute number of contentions */ static int lock_stat_cmp(const void *l, const void *r) { const struct lock_stat_data *dl = l, *dr = r; unsigned long nl, nr; nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr; nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr; return nr - nl; } static void seq_line(struct seq_file *m, char c, int offset, int length) { int i; for (i = 0; i < offset; i++) seq_puts(m, " "); for (i = 0; i < length; i++) seq_printf(m, "%c", c); seq_puts(m, "\n"); } static void snprint_time(char *buf, size_t bufsiz, s64 nr) { s64 div; s32 rem; nr += 5; /* for display rounding */ div = div_s64_rem(nr, 1000, &rem); snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10); } static void seq_time(struct seq_file *m, s64 time) { char num[15]; snprint_time(num, sizeof(num), time); seq_printf(m, " %14s", num); } static void seq_lock_time(struct seq_file *m, struct lock_time *lt) { seq_printf(m, "%14lu", lt->nr); seq_time(m, lt->min); seq_time(m, lt->max); seq_time(m, lt->total); } static void seq_stats(struct seq_file *m, struct lock_stat_data *data) { char name[39]; struct lock_class *class; struct lock_class_stats *stats; int i, namelen; class = data->class; stats = &data->stats; namelen = 38; if (class->name_version > 1) namelen -= 2; /* XXX truncates versions > 9 */ if (class->subclass) namelen -= 2; if (!class->name) { char str[KSYM_NAME_LEN]; const char *key_name; key_name = __get_key_name(class->key, str); snprintf(name, namelen, "%s", key_name); } else { snprintf(name, namelen, "%s", class->name); } namelen = strlen(name); if (class->name_version > 1) { snprintf(name+namelen, 3, "#%d", class->name_version); namelen += 2; } if (class->subclass) { snprintf(name+namelen, 3, "/%d", class->subclass); namelen += 2; } if (stats->write_holdtime.nr) { if (stats->read_holdtime.nr) seq_printf(m, "%38s-W:", name); else seq_printf(m, "%40s:", name); seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]); seq_lock_time(m, &stats->write_waittime); seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]); seq_lock_time(m, &stats->write_holdtime); seq_puts(m, "\n"); } if (stats->read_holdtime.nr) { seq_printf(m, "%38s-R:", name); seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]); seq_lock_time(m, &stats->read_waittime); seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]); seq_lock_time(m, &stats->read_holdtime); seq_puts(m, "\n"); } if (stats->read_waittime.nr + stats->write_waittime.nr == 0) return; if (stats->read_holdtime.nr) namelen += 2; for (i = 0; i < LOCKSTAT_POINTS; i++) { char ip[32]; if (class->contention_point[i] == 0) break; if (!i) seq_line(m, '-', 40-namelen, namelen); snprintf(ip, sizeof(ip), "[<%p>]", (void *)class->contention_point[i]); seq_printf(m, "%40s %14lu %29s %pS\n", name, stats->contention_point[i], ip, (void *)class->contention_point[i]); } for (i = 0; i < LOCKSTAT_POINTS; i++) { char ip[32]; if (class->contending_point[i] == 0) break; if (!i) seq_line(m, '-', 40-namelen, namelen); snprintf(ip, sizeof(ip), "[<%p>]", (void *)class->contending_point[i]); seq_printf(m, "%40s %14lu %29s %pS\n", name, stats->contending_point[i], ip, (void *)class->contending_point[i]); } if (i) { seq_puts(m, "\n"); seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1)); seq_puts(m, "\n"); } } static void seq_header(struct seq_file *m) { seq_printf(m, "lock_stat version 0.3\n"); if (unlikely(!debug_locks)) seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n"); seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1)); seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s " "%14s %14s\n", "class name", "con-bounces", "contentions", "waittime-min", "waittime-max", "waittime-total", "acq-bounces", "acquisitions", "holdtime-min", "holdtime-max", "holdtime-total"); seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1)); seq_printf(m, "\n"); } static void *ls_start(struct seq_file *m, loff_t *pos) { struct lock_stat_seq *data = m->private; struct lock_stat_data *iter; if (*pos == 0) return SEQ_START_TOKEN; iter = data->stats + (*pos - 1); if (iter >= data->iter_end) iter = NULL; return iter; } static void *ls_next(struct seq_file *m, void *v, loff_t *pos) { (*pos)++; return ls_start(m, pos); } static void ls_stop(struct seq_file *m, void *v) { } static int ls_show(struct seq_file *m, void *v) { if (v == SEQ_START_TOKEN) seq_header(m); else seq_stats(m, v); return 0; } static const struct seq_operations lockstat_ops = { .start = ls_start, .next = ls_next, .stop = ls_stop, .show = ls_show, }; static int lock_stat_open(struct inode *inode, struct file *file) { int res; struct lock_class *class; struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq)); if (!data) return -ENOMEM; res = seq_open(file, &lockstat_ops); if (!res) { struct lock_stat_data *iter = data->stats; struct seq_file *m = file->private_data; list_for_each_entry(class, &all_lock_classes, lock_entry) { iter->class = class; iter->stats = lock_stats(class); iter++; } data->iter_end = iter; sort(data->stats, data->iter_end - data->stats, sizeof(struct lock_stat_data), lock_stat_cmp, NULL); m->private = data; } else vfree(data); return res; } static ssize_t lock_stat_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct lock_class *class; char c; if (count) { if (get_user(c, buf)) return -EFAULT; if (c != '0') return count; list_for_each_entry(class, &all_lock_classes, lock_entry) clear_lock_stats(class); } return count; } static int lock_stat_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; vfree(seq->private); return seq_release(inode, file); } static const struct file_operations proc_lock_stat_operations = { .open = lock_stat_open, .write = lock_stat_write, .read = seq_read, .llseek = seq_lseek, .release = lock_stat_release, }; #endif /* CONFIG_LOCK_STAT */ static int __init lockdep_proc_init(void) { proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations); #ifdef CONFIG_PROVE_LOCKING proc_create("lockdep_chains", S_IRUSR, NULL, &proc_lockdep_chains_operations); #endif proc_create("lockdep_stats", S_IRUSR, NULL, &proc_lockdep_stats_operations); #ifdef CONFIG_LOCK_STAT proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL, &proc_lock_stat_operations); #endif return 0; } __initcall(lockdep_proc_init);